It is frequently desirable to provide ventilation to the interior of a boat or other watercraft. Many such craft, such as motor and sailboats, are provided with deck hatches having generally planar covers which normally fit more-or-less flush with the deck, but which can be propped in an open position to admit ventilating air to the interior of the craft. Although this arrangement may facilitate a flow of air through the hatch opening, it also permits the undesirable entry of rain water and spray which are commonly present in a marine environment.
A number of ventilator devices have been proposed for deflecting or otherwise facilitating the flow of air into the deck hatch of a boat. For example, U.S. Pat. No. 4,759,271, issued to Bliemeister, discloses a scoop-like ventilator which attaches to a hatch for turning the direction of moving air so that it passes down the hatch opening. The hatch cover and opening themselves remain generally exposed so that rain and spray can readily enter the hatch opening from the sides, and wind blown rain or spray may readily follow the simple arcuate path within the scoop and enter the hatch opening. Other wind-deflecting ventilators are disclosed in U.S. Pat. No. 4,938,123 (Hilton), U.S. Pat. No. 4,706,593 (Vale, Jr.), and U.S. Pat. No. 4,434,740 (Childs), each of which involve a scoop or other deflector mechanism for changing the direction of the wind flow so that it enters the hatch opening of the boat; however, each of these devices requires the removal of the conventional hatch cover with which the craft is originally equipped, and none of these devices has any provision for preventing rain and spray from entering the hatch opening. In fact, in the devices shown in the Hilton, Vale, Jr., and Childs patents, rain may simply fall vertically into the hatch opening.
U.S. Pat. No. 4,535,715, issued to McIntosh, discloses a deck ventilator which prevents water from flowing into the compartment should the ventilator be flooded. The ventilator is formed within a low dome having a window through which outside air enters; the air then circulates past a buoyant closure member and through a series of orifices to enter a ventilation duct. If a surge of water enters the ventilator, the buoyant closure member floats upwardly to close the orifice leading to the ventilation duct. The McIntosh device appears to be intended for more severe service than that normally encountered by pleasure craft, and in any event, is a complex and expensive device which would require special installation and could not be added as an attachment to an existing boat hatch cover.
Accordingly, there still exists a need for an inexpensive and effective ventilator which is mountable to a conventional deck hatch, and which facilitates the ventilation of the interior of the craft while effectively excluding rain and spray from entering therein.